1. Field of the Invention
The present invention is related to a security method of a portable device, and particularly to a security method of a portable device that utilizes a stolen flag set in a battery of the portable device or a lock flag set in a read-only memory to ensure the portable device is not powered on by a present user.
2. Description of the Prior Art
In the prior art, an owner of a portable device can enable a security function of the portable device through an application program stored in an operation system of the portable device. That is to say, the owner first sets a password of the portable device in a setup menu of a basic input/output system of the portable device. After the owner sets the password of the portable device in the setup menu of the basic input/output system, the basic input/output system can notify a keyboard controller to turn off the portable device to enable the security function of the portable device. After the security function of the portable device is enabled, the basic input/output system of the portable device can determine whether a password inputted to the portable device is correct and execute a corresponding operation according to a check result whenever the portable device is powered on. That is to say, when a password inputted to the portable device is correct, the basic input/output system can notify the operation system to perform a normal boot sequence according to boot sequence setting values stored in the basic input/output system; when a wrong password is inputted to the portable device more than a predetermined number of times, the basic input/output system can notify the keyboard controller to turn off the portable device.
In the prior art, after the security function of the portable device is enabled, the basic input/output system of the portable device can determine whether a password inputted to the portable device is correct. Meanwhile, the portable device supplies power to the basic input/output system, which means that probability of the portable device being cracked is increased. Therefore, the security method of the portable device provided by the prior art is not a good security method for the owner of the portable device.